摘要 |
A viscosimeter comprising a Zahn cup, a supply tank arranged to supply a liquid, the viscosity of which is to be measured, to the Zahn cup, a control mechanism operable to stop the supply of liquid to the Zahn cup once the latter has been filled to overflowing, and a timing mechanism arranged to measure the time taken for the Zahn cup to empty following operation of the control mechanism. The timing mechanism comprises an emitter-detector pair positioned to direct a sensing beam across the flow path of liquid which leaves the Zahn cup and a timer connected to commence a time measurement at the instant of operation of the control mechanism, and to stop the measurement at the instant the detector of the emitter-detector pair indicates an absence of liquid therebetween. Such a viscosimeter may be used in the measurement of the viscosity of ink used in a printing process, and the control of the viscosity in dependence upon that measurement.
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